By Jonny Dymond BBC correspondent in Istanbul

A package of reforms passed by the Turkish parliament is to be challenged by Devlet Bahceli, the leader of the largest group, the Nationalist Action Party.

Mr Bahceli told Turkish state television that he had asked colleagues to prepare an appeal to the country's constitutional court.

The reforms, which included the abolition of the death penalty, were passed in an effort to meet EU conditions for membership negotiations.

Devlet Bahceli wanted Ocalan executed

The Nationalist Action Party has argued long and hard against the adoption of what has become known as "the EU reforms".

For Mr Bahceli, the abolition of the death penalty was, in effect an amnesty for the captured Kurdish paramilitary leader Abdullah Ocalan.

He considers the lifting of restrictions on the use of the Kurdish language in education and broadcasting as a threat to the unity of the Turkish state.

Turkey fought for 15 years against Kurds who demanded greater autonomy.

More than 35,000 people were killed.

Mr Bahceli told Turkish state television that the aims of the Kurdish paramilitary group, the PKK, and those of the EU were connected.

Hardline supporters

He at one time enjoyed significant support for his hardline views.

In the 1999 election, he campaigned on a platform of executing Abdullah Ocalan.

Since then, he has often criticised what he has called "EU interference in Turkey's affairs".

It is not clear how serious the threat of the constitutional court might be for the passage of the reforms, but it is an indication that Mr Bahceli and his party will seek to take the campaign against the reforms into the forthcoming election.